Hello, syzbot found the following issue on: HEAD commit: bcf87687 Linux 5.8 git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=14184392900000 kernel config: https://syzkaller.appspot.com/x/.config?x=19b11af1e394136d dashboard link: https://syzkaller.appspot.com/bug?extid=7b1677fecb5976b0a099 compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15e1ff04900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+7b1677fecb5976b0a099@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: use-after-free in hci_conn_del+0x64e/0x6a0 net/bluetooth/hci_conn.c:630 Write of size 8 at addr ffff888089f54938 by task syz-executor.1/6870 CPU: 0 PID: 6870 Comm: syz-executor.1 Not tainted 5.8.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x18f/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 hci_conn_del+0x64e/0x6a0 net/bluetooth/hci_conn.c:630 hci_conn_hash_flush+0x189/0x220 net/bluetooth/hci_conn.c:1537 hci_dev_do_close+0x5c6/0x1080 net/bluetooth/hci_core.c:1761 hci_unregister_dev+0x1a3/0xe20 net/bluetooth/hci_core.c:3606 vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:340 __fput+0x33c/0x880 fs/file_table.c:281 task_work_run+0xdd/0x190 kernel/task_work.c:135 exit_task_work include/linux/task_work.h:25 [inline] do_exit+0xb72/0x2a40 kernel/exit.c:805 do_group_exit+0x125/0x310 kernel/exit.c:903 __do_sys_exit_group kernel/exit.c:914 [inline] __se_sys_exit_group kernel/exit.c:912 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:912 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45cce9 Code: Bad RIP value. RSP: 002b:00007ffd598b2c88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045cce9 RDX: 0000000000416741 RSI: 0000000000ca85f0 RDI: 0000000000000043 RBP: 00000000004c2983 R08: 000000000000000b R09: 0000000000000000 R10: 0000000002936940 R11: 0000000000000246 R12: 0000000000000008 R13: 00007ffd598b2dd0 R14: 0000000000136032 R15: 00007ffd598b2de0 Allocated by task 12376: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494 __do_kmalloc mm/slab.c:3656 [inline] __kmalloc+0x17a/0x340 mm/slab.c:3665 kmalloc include/linux/slab.h:560 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:313 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:308 security_file_open+0x52/0x3f0 security/security.c:1574 do_dentry_open+0x3a0/0x1290 fs/open.c:815 do_open fs/namei.c:3243 [inline] path_openat+0x1bb9/0x2750 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179 do_sys_open fs/open.c:1195 [inline] ksys_open include/linux/syscalls.h:1388 [inline] __do_sys_open fs/open.c:1201 [inline] __se_sys_open fs/open.c:1199 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1199 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 12376: save_stack+0x1b/0x40 mm/kasan/common.c:48 set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x103/0x2c0 mm/slab.c:3757 tomoyo_realpath_from_path+0x191/0x620 security/tomoyo/realpath.c:291 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x272/0x380 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:313 [inline] tomoyo_file_open+0xa3/0xd0 security/tomoyo/tomoyo.c:308 security_file_open+0x52/0x3f0 security/security.c:1574 do_dentry_open+0x3a0/0x1290 fs/open.c:815 do_open fs/namei.c:3243 [inline] path_openat+0x1bb9/0x2750 fs/namei.c:3360 do_filp_open+0x17e/0x3c0 fs/namei.c:3387 do_sys_openat2+0x16f/0x3b0 fs/open.c:1179 do_sys_open fs/open.c:1195 [inline] ksys_open include/linux/syscalls.h:1388 [inline] __do_sys_open fs/open.c:1201 [inline] __se_sys_open fs/open.c:1199 [inline] __x64_sys_open+0x119/0x1c0 fs/open.c:1199 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888089f54000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 2360 bytes inside of 4096-byte region [ffff888089f54000, ffff888089f55000) The buggy address belongs to the page: page:ffffea000227d500 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea000227d500 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0001e59308 ffffea00028b3908 ffff8880aa002000 raw: 0000000000000000 ffff888089f54000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888089f54800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888089f54880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888089f54900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888089f54980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888089f54a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches
